Building a scale helicopter

Step 1: Initial outline

I start out by taking a scale 3 view diagram and enlarging it to suit both the mechanics we would like to use and the overall size of the model we want to create. From this enlarged diagram we then cut out a profile from MDF board.

Step 2: Creating a 3D plug

The next step is to create a solid model in plaster. I do this by cutting out formers of the side profile of the model and gluing into place. Having a plastic kit of the model being built helps in making the side profile accurate.

The space between the formers is now filled in with foam to give a rough shape of the body.

This is carved to shape and then the whole body is covered in car body filler which is again sanded to shape. I make constant reference to the 3 view diagram and the formers to get the profile in all 3 views right.

Onto this smoothed body I put in much of the scale detail such as panel lines as I can.

Step 3: Create the Moulds

I now decide on where the mould is to be split for easy release e.g. tail removal, door openings etc. and the subsequent insertion of mechanics. I build these areas up with a layer of plasticine and put on a layer of gel coat and fibreglass matting to produce the moulds. These are then used to create the actual part which is then fitted back onto the plug after cutting out the area where it fits.

This continues until all the plug has been turned into moulds. (The red panels are the moulds in production)

Step 4: Create Body Kit

From the moulds I can now create a complete body shell using clear gel coat and epoxy resin with cloth. This creates a 'kit' of parts that is both light and strong. I reinforce any areas that are either weak or where stresses build up with Kevlar cloth and resin.

Step 5: Fit Mechanics and Engine

I now start putting the model together taking care to ensure engine and mechanics are well supported and easy to access for maintenance.

Step 6: Detail Interior/exterior

The scale detail for the interior is now made and fitted. These are copied as accurately as possible from detailed photos made of the full size.

Step 7: Test Fly

As the model comes together it is test flown to make sure the handling characteristics are stable.